Chapter 4 - Carbohydrates

Question 1

What are simple sugars?

Answer 1

Mono and disaccharides

Question 2

What are complex sugars?

Answer 2

Oligosaccharides and polysaccharides

Question 3

What are oligosaccharides?

Answer 3

Straight or branched chais of a few monosaccharides

Question 4

What are added sugars?

Answer 4

Sugars and syrups added to foods or beverages when they are processed or prepared

Question 5

What are free sugars?

Answer 5

Sugars that are added to foods by manufacturers or consumers, as well as naturally present in honey, syrups, and fruit juices

Question 6

What is the difference between added and free sugars?

Answer 6

Free sugars includes added sugars + naturally present sugars

Question 7

What sugar is used for energy in the body?

Answer 7

Glucose

Question 8

What is the formula of glucose?

Answer 8

C6H12O6

Question 9

How is corn syrup changed to high fructose corn syrup?

Answer 9

Glucose in enzymatically converted to fructose

Question 10

What does HFCS 90, HFCS 55, HFCS 42 mean?

Answer 10

90%, 55%, 42% fructose while the remaining % is glucose

Question 11

What has increased HFCS intake been linked to?

Answer 11

Obesity; childhood obesity

Question 12

Why is HFCS worse than other sugars?

Answer 12

While it has the same other energy yield, it is metabolized differently

Question 13

How is fructose metabolized?

Answer 13

Metabolized in the liver rather than the SI where it is readily converted to fat

Question 14

How is sucrose metabolized?

Answer 14

It is digested in the intestines by sucrase which assists in regulation of breakdown and release fructose into the blood stream

Question 15

What is lactose composed of?

Answer 15

Galactose + Glucose

Question 16

What is sucrose composed of?

Answer 16

Glucose + Fructose

Question 17

What is maltose composed of?

Answer 17

Glucose + Glucose

Question 18

What is the bond between sugars in a dissacharide?

Answer 18

Glycosidic bond

Question 19

How is glucose stored in the body?

Answer 19

As glycogen in the liver and some in the muscles

Question 20

What is gluconeogenesis?

Answer 20

• Process where sugars are made from non sugars (ex. lactic acid)
• Occurs when the dietary intake is insufficient to supply th ebody

Question 21

What is the structure of glycogen?

Answer 21

Polymer of glucose units in long, highly branched chains

Question 22

How is starch broken down in digestion?

Answer 22

Starch to maltose to glucose

Question 23

What is the amylose:amylopectin ratio in starch?

Answer 23

20-30%:70-80%; amylose is unbranched, amylopectin is highly branched

Question 24

What is resistant starch?

Answer 24

Starch that is not chemically a fibre but acts like a soluble fibre in the GIT, as resistant to digestion and absorption

Question 25

What causes resistant starch to be resistant?

Answer 25

* High in amylose * Structure of the granule protecting the starch in a plant (raw potato, banana)

Question 26

What kind of carbohydrate is fibre considered?

Answer 26

Non-starch polysaccharide

Question 27

Why is fibre not digested?

Answer 27

Its bonds cannot be hydrolyzed by digestive enzymes, which allows no energy to be yielded

Question 28

What is the difference between soluble and insoluble fiber?

Answer 28

* Soluble dissolved in water, acting as a colloid * Insoluble cannot be dissolved, acts bulk to stool

Question 29

What is the structural difference between soluble and insoluble fiber?

Answer 29

Soluble fiber is higher in amylopectin, insoluble is higher in amylose

Question 30

What is cellulose?

Answer 30

A complex CHO which adds rigidity to plant cell walls, vegetables and fruits, and legumes

Question 31

How are the glucose units joined in cellulose?

Answer 31

Beta 1,4 glycosidic linkeages

Question 32

What are pectins?

Answer 32

Complex CHO found in fruits and vegetables. It has a linear backbone of 1 type monosaccharide units

Question 33

What are mucilages?

Answer 33

Complex CHO similar to pectins; has mixed monosaccharide backbones and branches

Question 34

What are phenol polymers?

Answer 34

Non-polysaccharides that increase tensile strength * Lignin, cutins, tannins

Question 35

What are prebiotics?

Answer 35

A bio-functional food component which consists of non-digestible oligosaccharides. They are fermented in the colon.

Question 36

What are the functions of prebiotics?

Answer 36

* Stimulate the growth of beneficial bacteria * Modulate the microflora

Question 37

How is glucose and galactose absorbed?

Answer 37

Through active transport process * transporter: BBM Sodium Glucose Transporter

Question 38

How is fructose absored?

Answer 38

Facilitated diffusion * Transporter: BBM Glucose transport protein

Question 39

What happens after glucose, galactose, or fructose are first absorbed?

Answer 39

They both move to the GLUT2 to get absorbed into the blood stream